@edcmikegold --
Just file the D-40B with DC. No need to file a DC tax return.
2020 D-40B | otr (dc.gov)
If you haven't done so already, submit form D-4A to your DC employer to stop the DC withholding. Here's a link to that form:
https://otr.cfo.dc.gov/sites/default/files/dc/sites/otr/publication/attachments/2018%20D-4A.pdf
Retrieving the DC refund and paying MD is a manual process; there is no form and it can't be done online.
If your employer cannot or will not withhold MD taxes for you, you should begin making quarterly estimated tax payments to MD. This link explains:
https://www.marylandtaxes.gov/individual/tax-compliance/estimated-tax-payments-for-ind.php
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
